Stima dell’età di Silurus glanis mediante peso del cristallino

Estimation of age in fish is fundamental to know the growth rate and other biological parameters. Here is presented a first effort to use eye lens weight and diameter in order to determine age in Silurus glanis. Eyes were obtained from a sample of Silurus collected in Campotto lakes and dried lenses were then measured in weight and diameter with a precision balance and digital calliper. Correlation with an estimation of age based on the vertebral body was calculated. The best results came from the weight as the diameter produced a less informative curve. No significant differences between genders were detected.